------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 15146 at lib/refcount.c:25 refcount_warn_saturate+0x201/0x290 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 15146 Comm: kworker/u4:8 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: qrtr_ns_handler qrtr_ns_worker
RIP: 0010:refcount_warn_saturate+0x201/0x290 lib/refcount.c:25
Code: 01 31 ff 89 de e8 ef b9 b2 fd 84 db 0f 85 bb fe ff ff e8 62 b3 b2 fd 48 c7 c7 a0 30 bf 89 c6 05 ff 75 a9 09 01 e8 3d 41 09 05 <0f> 0b e9 9c fe ff ff e8 43 b3 b2 fd 0f b6 1d e4 75 a9 09 bf 01 00
RSP: 0000:ffffc9001641f9f8 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8880260b3580 RSI: ffffffff815b9465 RDI: fffff52002c83f31
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815b78bb R11: 0000000000000000 R12: ffff888011950000
R13: ffff888021f93000 R14: ffff88802471f030 R15: ffff88802471f034
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004d2410 CR3: 0000000018d42000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __refcount_add include/linux/refcount.h:199 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 kref_get include/linux/kref.h:45 [inline]
 qrtr_node_acquire net/qrtr/qrtr.c:201 [inline]
 qrtr_node_lookup net/qrtr/qrtr.c:394 [inline]
 qrtr_send_resume_tx net/qrtr/qrtr.c:1004 [inline]
 qrtr_recvmsg+0x84a/0x980 net/qrtr/qrtr.c:1067
 sock_recvmsg_nosec net/socket.c:886 [inline]
 sock_recvmsg net/socket.c:904 [inline]
 sock_recvmsg net/socket.c:900 [inline]
 kernel_recvmsg+0x110/0x160 net/socket.c:929
 qrtr_ns_worker+0x15a/0x17e0 net/qrtr/ns.c:684
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296